Depending on the type of gutter and the amount and type of build-up, there are several gutter cleaning tools available. Some tools can be purchased, some may already be hanging around your house, and others can be made in a few easy steps.
A gutter rake is useful for gutters filled mostly with leaves and other lightweight debris. It is also most useful if your gutters are less than half full. The gutter rake is 4 to 5 feet long and allows you to scrape out your gutters while standing on a ladder. Each end of the rake is shaped differently, allowing you to perform two different functions. On one end is a straight piece that can be used to pull debris toward you. On the other end is a curved piece that ends in an L shape. This tool allows you to push debris under gutter joints and other tight spots so that you can then remove the debris by hand. Both ends of the gutter rake can be used with either wet or dry debris. Many gutter rakes come with a threaded end that can be attached to a broom handle or extension pole, extending your reach even further for very long gutters or hard to reach areas. Although a pole or hoe will work in place of a gutter rake, both tools take longer and have less leverage than a gutter rake.
Another useful tool is a gutter scoop. To make a gutter scoop, simply find a recycled plastic jug with a handle and cut out the bottom at a slight angle. Milk jugs work fine, but heavier plastics, such as those found on bleach bottles or fabric soften bottles will stand up better. Though you can make your own, a purchased gutter scoop is specifically designed to fit your gutters, will likely last longer and usually works better for lifting out heavy debris. In place of purchasing a gutter scoop, you can also use a small hand trowel. Gutter Scoops work with all types of debris, both dry and wet, lightweight and heavy.
If your gutter debris is dry and fairly lightweight, then a leaf blower may be your fastest, easiest option. Simply walk along the roof next to your gutters and blow out the debris. Be sure to move any patio furniture before using this method. Though you can use either a gas or electric leaf blower, the gas model is far superior as it has more power and is cordless, allowing you more flexibility.
Finally, for light to medium debris, you can try using a shopvac to simply suck up the debris. And extra long hose will help with this method.